(1) Field of the Invention
This invention relates to medical materials having excellent compatibility with living bodies, especially, a superb antithrombotic property and to their production process.
(2) Brief Description of the Prior Art
Medical materials used in direct contact with blood, such as artificial vessels and artificial heart valves, encounter the extremely serious problem of thrombus development.
Materials containing collagen, such as animal carotid arteries and human umbilical veins, have been conventionally used as artificial vessel materials. In artificial vessels making use of such materials, it has been known that they are susceptible to developing thrombi and are thus often obstructed in the initial stages of their use. Namely, when blood is brought into contact with surfaces of such artificial vessles which surfaces are formed of foreign bodies other than endothelial cells, the blood immediately forms thrombi. It is thus most important for successful blood-contacting organs such as artificial vessels, artificial valves and artificial hearts to suppress the thrombus formation and, if possible, to achieve the formation of pseudoendotheliums.
A variety of intensive research have been carried out to suppress thrombus formation. Under the circumstances, no ideal antithrombotic medical materials have yet been developed.